Electric railway-signal



" UNITED STATES PATENT OFFICE.

, EDWARD L. ononrr, or SOMERVILLE, MASSACHUSETTS.

ELECTRIC RAILWAY-SIGNAL.

sPEcIFIoA'rIoN forming part of Letters retent ve. 272,464, dated February 20, 1883.

Application filed November 3, 1882. (No model.)

To all whom it may concern Be it known thatI, EDWARD LEVI Onon'r'r, of Somerville, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Electric Rail way-Signals, of which the following is a specification.

My invention relates to improvements in electrical circuits in which one rail of a railwaytrack is divided into insulated sections of any desired length and'the electric current is sent from one section through another section and back through the'other continuous rail; and the objects of my improvements are to give an audible signal to the engineer, by which he will know whether the section ahead is free or not from obstructions, and alsowhether a part of his train has been left on the section just passed over, and to signal the approach of a train to a station or road-crossing. To attain these objects I arrange the circuits and electric generator as shown'in the accompanying drawings, in which- Figure l is a side elevation of alocomotive, showing the location of the dynamo-generator and its connections with the alarm in the cab and the contact-brushesin front. Fig. 2 shows the manner of attaching the contact-brushes to a cow-catcher. Figs. 3 and 4 show a doubletrack railway with my circuits, and may be considered separately to illustrate the arran gement for a single track.

A dynamo-electric machine, A, is operated by an axle of any one of the wheels and furnishes the current for actuating all the signals. It will be obvious that the power required will be insignificant, and that the requisite current might be obtained from any of the well-known batteries; but these latter are objectionable and require constant attention, so that I prefer to' use the dynamo-machine, as above stated. This dynamo-machine A is'connected to the iron-work of the engine, and through that to the rails by the wire a. A wire, a, connects it to a wire, B, which connects the coil of one pole of the magnet G in the cab with the two contact-brushes D D, placed at the hereinafter set forth. To complete the circuit for sounding the alarm insthe cab, I place one or more contact-plates, F F F, midway between the rails.

. tion adjacent to the one they are in by means of the wires ff f Each insulated section is connected with the continuous rail'opposite by the wires and the spring-supported armatures of the magnetsf flf on the well-known principle of automatic circuit-breakers. All the switches are arranged to make an electrical connection'between therails when open toasiding. The circuit-breakers are always located so that theywillmake thelongestpossiblecircuit. The object of this is that. any obstruction or the like will shunt-circuit them and cut them out. Suppose the engine (moving as indicated by the arrow) to be near the end of section 1. The central contact-brusln D will strike the first of the plates F and complete the circuit from the generator eg through the wire B, the magnet C, the wire E, contact-brush D contact-plate F, wir'ef, insulated section 2, circuit-breaker f, the continuous rail, the ironwork of the engine, the short wire a, to the generator A, and thereby cause a rapid vibration of the armature of the magnet O and a continuous ringing of the gong in the cab, which is the signal for all clear. Now, suppose section 2 to be obstructed by a train or detached car or a misplaced switch, or anything that will make an electrical connection between the insulated rail and the continuous rail, so as to form a shorter circuit than that through the circuitbreaker, as above described, it is evident that such obstruction will cut out the circuit-breaker f and,'instead of a continuous rapid ringing of the gong in the cab, there will be but one blow while the brush is in contact with a plate. This is the signal for danger, andthe engineer would be governed accordingly. After passing a section the engineer is notified of its being left clear or whether it is obstructed by one or more cars having become detached by means 'of contact-plates {1, (one of which only is shown in the drawings,) through which the current is sent backward in the same manner as before described. These plates 9 also serve as advance signals for an engine backing up. Of course in a single-track railway both sets of contactplates are requisite. The signals I I at stations, draw-bridges, road-crossings, 820., are similarly operated by the contact-plates h, on one side of the center of the track and the contact-brushes D D on both sides of the cowcatcher, two of these brushes being used, so as to insure contact whichever way the engine may be moving. The current is conveyed to the signals by the wire '1'. On a double-track road, however, the continuous rail of the other track may be used for this purpose. A suitable switch is placed on the incomplete engine circuit, within reach of the engineer, by means of which he can complete this circuit at any time, so as to ascertain, in case of failure to receive a signal, whether the fault is in the generator or engine-circnit or in the track-circuit. The en gineersoon becomes accustomed tohearing the signals at certain points on the road,

and a failure of such signal, from any cause, will attract his attention as readily as the sounding of the alarm would have done. For this reason audible signals are much to be preferred, as a security against accident, to the visible signals usually employed in railways.

I claim as of my own invention In an electric circuit for railway signaling, the combination of an automatic circuit-breakin g connection between an insulated section of one rail of a track and the other continuous rail, contact-plates electrically connected to the insulated sections, and contactbrushes, generator, and alarm on the engine, forming parts of an incomplete circuit, which is completed only when a contact-brush touches one of the contact-plates, the circuit-breakin g connection being located as described, so as to be shortcircuited or cut out by the wheels of a car or the like on its section, as set forth.

EDWARD L. ()RUUTT.

Witnesses:

G. B. MAYNADIER, JOHN R. SNow. 

